Electrified jetting is a process to develop liquid jets having a nanometer-sized diameter, using electro-hydrodynamic forces. When a pendant droplet of conducting liquid is exposed to an electric potential of a few kilovolts, the force balance between electric field and surface tension causes the meniscus of the pendent droplet to develop a conical shape, the so-called Taylor cone. Above a critical point, a highly charged liquid jet is ejected from the apex of the cone. This well-established process has been employed by two processes, i) electrospraying and ii) electrospinning. In electrospraying, the ejected liquid jet is eventually fragmented due to instabilities and forms a spray of droplets. Among the various applications, production of charged gas phase ions of bio-macromolecules for mass spectroscopy is the most widely used. Using polymer solutions or melts as jetting liquids, electrospinning gives a way to develop fibers whose diameters are a few orders of magnitude smaller than those available from conventional spinning. Only during the last decade, electrospinning has witnessed increasing attention and nanofibers have been spun from a wide variety of polymers. In the last decade, electrospinning has witnessed increasing attention and nanofibers have been spun from a wide variety of polymers.
Recently several multi-component jetting systems have been reported employing capillaries with different geometries. Among those is a coaxial core-shell geometry, which has outer and inner liquid-feeding channels and which produces stable cone jets having sustained core and shell layers. Much less is known about alternative geometries of multi-component jetting such as a side-by-side configuration.
Anisotropic multi-phasic nano-objects possessing two distinct phases may establish significant advances in nanotechnology and may have broad impact in areas, such as microelectronics and biotechnology. The possibility of selective modification of each side of the biphasic object makes this system very attractive and versatile for electronic and biomedical applications.
Accordingly, there is a need for improved methods of forming nanometer sized particles and for multiphasic particles with unique chemical properties.